History clamping for denoising dynamic ray-traced scenes using temporal accumulation

ABSTRACT

Approaches presented herein can reduce temporal lag that may be introduced in a generated image sequence that utilizes temporal accumulation for denoising in dynamic scenes. A fast historical frame can be generated along with a full historical frame generated for a denoising process, with the fast historical frame being accumulated using an exponential moving average with a significantly higher blend weight. This fast history frame can be used to determine a clamping window that can be used to clamp a corresponding full historical value before, or after, reprojection. The fast historical blend weight can be adjusted to control the amount of noise versus temporal lag in an image sequence. In some embodiments, differences between fast and full historical values can also be used to determine an amount of spatial filtering to be applied.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of, and claims priority to, U.S.patent application Ser. No. 17/067,417, filed Oct. 9, 2020, and entitled“History Clamping for Denoising Dynamic Ray-Traced Scenes Using TemporalAccumulation,” which is hereby incorporated herein in its entirety forall purposes.

BACKGROUND

As the quality of display devices—along with user expectations—continueto increase, there is a need to continually increase the quality ofcontent to be displayed. This can include tasks such as removing noiseand reducing artifacts in rendered images, such as may correspond toframes of content for video games or animation. Certain conventionalapproaches utilize processes such as temporal accumulation to attempt todenoise various effects, such as shadows, reflections, ambientocclusion, and direct lighting for ray tracing applications. In manysituations however, this can lead to temporal lag for dynamic scenes,which may result in noticeable ghosting due to this accumulation beingunable to quickly and accurately account for changes in dynamic scenes.Existing approaches to managing temporal lag have either failed toadequately reduce the undesired effects, or have added undesirableadditional computational requirements and complexity.

BRIEF DESCRIPTION OF THE DRAWINGS

Various embodiments in accordance with the present disclosure will bedescribed with reference to the drawings, in which:

FIGS. 1A, 1B, 1C, and 1D illustrate images rendered for a dynamic scene,according to at least one embodiment;

FIG. 2 illustrates an example image generation system, according to atleast one embodiment;

FIGS. 3A, 3B, 3C, 3D, and 3E illustrate stages in an example clampingprocess, according to at least one embodiment;

FIG. 4 illustrates an example history clamping process, according to atleast one embodiment;

FIG. 5 illustrates an example image generation system includingclamping-aware blur capability, according to at least one embodiment;

FIG. 6 illustrates a process for applying clamping-aware blur to animage, according to at least one embodiment;

FIG. 7 illustrates an example data center system, according to at leastone embodiment;

FIG. 8 illustrates a computer system, according to at least oneembodiment;

FIG. 9 illustrates a computer system, according to at least oneembodiment;

FIG. 10 illustrates at least portions of a graphics processor, accordingto one or more embodiments; and

FIG. 11 illustrates at least portions of a graphics processor, accordingto one or more embodiments.

DETAILED DESCRIPTION

Approaches in accordance with various embodiments can overcomedeficiencies in existing approaches to image generation. In particular,various embodiments can provide for improved denoising of imageartifacts, such as artifacts that may be introduced by ray tracing orother image generation or rendering techniques. In a system forgenerating images or video frames for a dynamic scene, there can bevarious artifacts resulting from changes in the scene. Temporalaccumulation can be used to attempt to minimize a presence of at leastsome of these artifacts. A temporal accumulation approach can retaininformation from previously-generated frames in a sequence to attempt toprovide at least some amount of temporal smoothing, where colors ofpixels in a current frame are blended with colors from previous framesto attempt to minimize ghosting and other such artifacts, and providefor a smoother transition of colors in the scene. When blending colorsfrom a current rendered frame and historical frames, it can be desirableto strike an appropriate balance when determining a blending weight. Ifthe colors of the current frame are weighted too heavily, theeffectiveness of the smoothing may be reduced, resulting in an increasein artifacts. Conversely, there may be undesirable temporal lag if thehistorical colors are weighted too heavily.

As an example, consider images FIGS. 1A through 1D. As depicted in theimage 100 of FIG. 1A, there is a light source 102 on a wall, which maycorrespond to a window, lighted poster, mirror, or other such source oflight. Visible on a nearby floor is a region 104 where the emitted orreflected light is brighter, resulting in a brighter coloring of thosepixels resulting from the light source. In some embodiments, this maycorrespond to a dynamic scene where the positions of objects in acurrent view can change. For example, in image 120 of FIG. 1B there mayhave been a pan motion of a virtual camera, or other such motion, thatcaused a position of the light source 102 in the image to move relativeto the prior frame. Many rendering engines will detect this motion orprovide information about this motion, as may relate to motion vectorsfor various objects in the scene. This motion information may notindicate other related changes, however—as may correspond to, forexample and without limitation: shadows, lighting, reflections, orambient occlusions—that may change as a result of this motion, such asmay be due to ray tracing involving one or more moving objects in ascene. If temporal smoothing is applied, the impact of the historicaldata may cause changes in the pixels of such a region or object, such asbright region 104, to not move together with the corresponding object102. As illustrated in FIG. 1B, there may be little to no movement ofthis bright region 104 in an initial frame where light source 102 movedto the right. As illustrated in image 140 of FIG. 1C, there will be sometemporal lag where bright region 104 will follow movement of lightsource 102 with some delay, until the bright region arrives at theappropriate location as illustrated in image 160 of FIG. 1D. Factorssuch as the blending weight and amount of historical data utilized canimpact an extent of this lag, which in some cases may be quitenoticeable and may be distracting to a viewer, or may at least reduce aperceived realism of the scene. It is desirable in at least some systemsto retain advantages of temporal smoothing and accumulation, whilereducing an impact of temporal lag on a dynamic scene.

One of the most common temporal accumulation techniques is temporalanti-aliasing (TAA). One technique that was developed to improve TAA isusing history clamping as a way of dealing with dynamic events.Conventional temporal accumulation approaches typically involve the useof two buffers. A first buffer is a history buffer that contains asignificant number of frames, such as 30 for a given application but mayrange from about 10 to 100 frames or more for other applications. Theseframes can be accumulated over time with a use of exponential movingaverage. A second buffer is a current buffer that contains data for acurrent frame, such as a most recent frame received from a renderingengine. In a conventional approach, this history buffer (h) is to bere-projected to the camera position for the current frame (c), andcomposited with the data for the current frame using, for example, anexponential moving average blend weight (w). In at least oneimplementation, a pixel value (p) for an output frame can be given by:p=w*c+(1−w)*hTo deal with temporal lag, the history value is typically clamped to amin/max window of a pixel neighborhood (e.g., a 3×3 pixel window) fromthe current frame before temporal anti-aliasing. Other metrics can beused instead of min/max, such as may involve calculating mean andvariance of a neighborhood and clamping the history value to thatdistribution. Such an existing approach is often not adequate for verynoisy signals or dynamic scenes.

Another prior approach to attempt to manage temporal lag is A-SVGF, aspatiotemporal variance-guided filtering technique. Such a process iseffectively a filtering technique that can take as input a noisy frameand reconstruct that into a full image with reduced noise. A-SVGF canproduce desired results in many instances, but the time needed toproduce these results may be too long for a ray tracer operating in realtime at modern frame rates, such as at least 60 frames per second (fps).A-SVGF uses temporal gradients to minimize the temporal lag whiledenoising path traced imagery; however, since it must be integrateddeeply into the renderer, it adds rendering cost and complexity to therenderer. Some games utilize velocity of the occluder to guide temporalaccumulation of shadows. While this is a relatively simple solution, itcomes with limitations and corner cases that are hard to solve. Forexample, if both occluder and receiver move, guiding the temporalaccumulation becomes complicated. Further, when denoising ray traceeffects, the current frame signal is typically very noisy and is notsuited for calculating neighborhood clamping window since that windowends up being noisy as well.

Approaches in accordance with various embodiments utilize a responsiveor “fast” history buffer together with a conventional history buffer andcurrent frame buffer. A fast history buffer can utilize a much higherblend weight than is used for a conventional or “full” history buffer,such as on the order of a magnitude higher, such that fewer historicalframes contribute to the fast history. This fast history can be used todetermine a clamping window for a current frame in order to clamp thenormal history value before, or after, re-projection. In at least oneembodiment, a fast history clamping blend weight can be used as anintuitive knob to determine an appropriate balance between an amount ofnoise versus an amount of temporal lag in a scene. In at least oneembodiment, a full history is maintained to provide for more accuratetemporal smoothing in the absence of conditions causing clamping to beapplied.

FIG. 2 illustrates components of an example image generation system 200that can be utilized in accordance with various embodiments. In at leastone embodiment, content such as video game content or animation can begenerated using a renderer 202, rendering engine, or other such contentgeneration system or component. This renderer 202 can receive input forone or more frames of a sequence, and can generate images or frames ofvideo using stored content 204 modified based at least in part upon thatinput. In at least one embodiment, this renderer 202 may be part of arendering pipeline that can provide functionality such as deferredshading, global illumination, lit translucency, post-processing, andgraphics processing unit (GPU) particle simulation using vector fields.

In some embodiments an amount of processing necessary for generatingsuch complex, high-resolution images can make it difficult to renderthese video frames to meet current frame rates, such as at least sixtyframes per second (fps). In at least one embodiment, a renderer 202 maybe used to generate a rendered image at a resolution lower than one ormore final output resolutions in order to meet timing requirements andreduce processing resource requirements. A renderer may instead render acurrent image (or a current image may otherwise be obtained) that is ata same resolution as a target output image, such that no upscaling orsuper-resolution procedure is required or utilized. In at least oneembodiment, if a current rendered image is of a lower resolution, thenthis low-resolution rendered image can be processed using an (optional)upscaler 206 to generate an upscaled image that represents content ofthe low resolution rendered image at a resolution that equals (or is atleast more closely approximates) a target output resolution.

This current rendered image, whether upscaled or not, can be provided asinput to an image reconstruction module 208 that can generate a highresolution, anti-aliased output image using the current image and datafor one or more previously-generated images, as may be at leasttemporarily stored in a full history buffer 216 or other such location.The previously-generated image can be a single historical image in someembodiments, where pixel (e.g., color) values are accumulated over anumber of prior frames using, for example, an exponential movingaverage. In at least one embodiment, this image reconstruction module208 can include a blending component 210, as may comprise one or moreneural networks. In at least one embodiment, this may include at least afirst optical flow network (OFN) for generating motion vectors or otherinformation indicative or movement between adjacent frames in asequence. In at least one embodiment, this can include an externallyrecurrent, pre-image reconstruction, unsupervised optical flow network.In at least one embodiment, this may also include at least a first imagereconstruction network (RN) to utilize these motion vectors in order tocorrelate positions in a current image and a previous (historical) imageand infer an output image from a blending of those images. In at leastone embodiment, this blending of a current image with a historical imageframe can help with temporal convergence to a nice, sharp,high-resolution output image, which can then be provided forpresentation via a display 212 or other such presentation mechanism. Inat least one embodiment, a copy of this output image can also beprovided to a history manager 214, which can cause pixel values to beaccumulated with values from prior historical frames using anaccumulation factor, in order to enable this accumulated historical datato be represented by a single frame to conserve memory and reduceprocessing requirements. In at least one embodiment, a weighting factorcan cause pixel values from older frames to contribute less to anaccumulated pixel value. This historical image frame can then be storedto a full history buffer 216, or another such storage location, forblending with a subsequently-generated image in this sequence.

As mentioned, real-time temporal reconstruction of an image utilizesinformation from one or more prior frames after some warping to align toan image being generated for a current frame. In at least oneembodiment, such warping is utilized at least in part because imagereconstruction is simplified when pixel information in these images isaligned. In at least one embodiment, however, proper image warpingutilizes not only information from a prior frame, but also additionalinformation about how objects move between these frames. In at least oneembodiment, this can include computer vision or optical flow data, whichmay be represented by a set of motion vectors. In at least oneembodiment, this may include motion vectors for each pixel location, orat least pixel locations for which there is movement. This motioninformation can help to better warp image information and aligncorresponding pixels or objects. Motion vector information may beprovided by a rendering engine for a game or application, but asmentioned this may not account for corresponding changes for aspectssuch as reflections or lighting that may result from a ray-tracingprocess. This blending may then result in temporal lag as discussedpreviously. Various prior approaches can apply clamping to attempt toreduce temporal lag, but come with various deficiencies presentedpreviously.

Accordingly, in at least one embodiment history manager 214 can alsogenerate a responsive or “fast” historical frame that can be stored to afast history buffer 218. This fast frame can be generated using adifferent accumulation weight, which in some instances may be around anorder of magnitude larger than an accumulation weight used to generate afull historical image. In one example, an accumulation weight for a fasthistorical frame is about 0.5, while an accumulation weight for a fullhistorical frame is about 0.05. In at least one embodiment, this canresult in a fast historical frame including data accumulated over a mostrecent two to four frames, while a full historical frame may includedata accumulated over a most recent twenty to one hundred frames. Theseweights may be learned over time or set by a user, and may beconfigurable through one or more interfaces, among other such options.

In at least one embodiment, this fast history frame can be pulled fromthe fast history buffer 218 when the image reconstruction module 208 isto generate a next output frame in the sequence. As mentioned, it can bedesirable to blend a newly rendered current frame with a full historicalframe to provide for at least some temporal smoothing of the image toreduce a presence of artifacts when displayed. Instead of clamping basedon the full historical frame, however, the clamping determination can bemade using the fast historical frame, which will include historical dataaccumulated over only a small number of previous frames, such as theprior two to four frames in a sequence. A clamping module 220 cananalyze a number of pixels in a region around a pixel location to beanalyzed, such as pixels in a 3×3 pixel neighborhood of the fasthistorical image. Neighborhoods larger than 3×3 can be used, but mayintroduce additional spatial bias for at least some dynamic scenes. Theblending module can then determine a distribution of expected pixel(e.g., color) values for that pixel. This expected distribution can thenbe compared against a value for a corresponding pixel in the fullhistorical image. If the full historical pixel value is outside thedistribution of expected values, then the pixel value can be “clamped”to, for example, the closest value to the historical pixel value that iswithin the distribution of expected values. Instead of clamping to thecurrent value, which may lead to ghosting, noise, or other artifacts,this approach can clamp to an intermediate value that is determinedusing the fast historical frame. The blending module can then take thevalues, clamped or otherwise, from the full historical frame and blendaccordingly with pixels of the current frame as discussed herein. Thisnew image can then be processed by the history manager 214 to generateupdated historical images to be stored in the historical buffers 216,218 for reconstructing a subsequent image.

Such a clamping process may be better understood with respect to FIGS.3A through 3E. As discussed, clamping analysis can be performed using afast historical frame. This historical frame is generated byaccumulating historical information for the individual pixels using anidentified accumulation factor or blend weight. As mentioned, while anaccumulation factor for a full historical frame may be on the order ofaround 0.05, an accumulation factor for a fast frame may be much larger,such as on the order of 0.5, such that contributions from older framesare minimized much more quickly. Minimal additional effort is needed toaccumulate and re-project fast history in a system that is alreadyaccumulating full or “long” historical information. In this example, theblend weight is used with an exponential moving average of past framedata in order to avoid storing data for each of those past frames inmemory. Data accumulated in history is multiplied by (1−weight) and thencombined with the data in the current frame, which may be multiplied bythe blending weight. In this way, a single historical frame can bestored in each buffer where contributions of older frames are lessenedaccording to the recurrent accumulation approach. In at least oneembodiment, this accumulation weight can be adjusted automatically basedon any of a number of factors, such as a current frame rate to beprovided, total variance, or amount of noise in produced frames.

When a clamping analysis is to be performed, data for points in asurrounding neighborhood (e.g., a 3×3 neighborhood) for each pixellocation in a fast historical frame can be determined. These pixelvalues can each be thought of as color points in a three-dimensionalcolor space, as illustrated by points 302 in plot 300 of FIG. 3A. Whilered-green-blue (RGB) color space may be utilized in various embodiments,there may be other color spaces (e.g., YIQ, CMYK (cyan, magenta, yellow,and black), YCoCg, or HSL (hue, saturation, brightness value)) withother numbers of dimensions utilized in other embodiments. Asillustrated in FIG. 3A, these points from the neighborhood are locatedin a region of color space. When determining pixel values for ahistorical frame that may be reasonably expected based on these points,various approaches can be utilized to determine these expected values.The expected value can be at, or within, a volume defined by thesepoints, or a reasonable amount of distance outside this volume, as maybe configurable and may depend at least in part upon the approach taken.In an example approach of FIG. 3B, the plot 320 shows an expectationregion 322 surrounding these points. Any of a number of projection orexpectation algorithms or networks can be utilized to determine or infera size and shape of this expectation region. In one embodiment, a convexhull-based approach can be utilized. FIG. 3C illustrates another exampleapproach, wherein a bounding box 342 can be determined for those pointsin color space as illustrated in the plot 340. The bounding box can bedetermined using a number of different bounding algorithms, which mayinclude different amounts of buffering around these points in eachdirection. In at least one embodiment, this expectation region can bedetermined using a mean and variance distribution. Various otherregions, boxes, ranges, or determinations can be used as well within thescope of the various embodiments.

Once this expectation range or region is determined from the fasthistorical frame, the corresponding pixel from the full historical framecan be identified. The plot 360 of FIG. 3D illustrates a historicalpixel value 362 in color space relative to the expectation region. Thehistorical pixel can be compared against this expectation region todetermine whether the pixel falls inside, or outside, the expectationregion. If the pixel value is within the expected region then thecorresponding full historical pixel value can be utilized and noclamping applied. It may be the case, however, that the historical point362 may be outside the region, as illustrated in FIG. 3D. In this case,clamping can be applied to the historical value. Plot 380 of FIG. 3Eillustrates that the pixel value can be “clamped,” or adjusted so thatit falls within the expected range. In this example, the clamped value382 to be used for the full historical frame is the “clamped” valuewithin the expectation range that is closest in color space to the fasthistorical pixel value. In one embodiment, this can involve clamping byapplying a min/max analysis along each dimension of color space todetermine the new clamped value.

FIG. 4 illustrates an example process 400 for performing clamping ofhistorical data that can be performed in accordance with variousembodiments. It should be understood that for this and other processespresented herein there can be additional, fewer, or alternative stepsperformed in similar or alternative order, or at least partially inparallel, within scope of various embodiments unless otherwisespecifically stated. In this example, a current frame is received 402from a rendering engine, or otherwise obtained. This can be a currentframe or image in a series of frames or images, such as may be generatedfor animation, gaming, virtual reality (VR), augmented reality (AR),video, or other such content. The current frame can be blended 404 witha corresponding fast history frame, using appropriate blend factors.Pixel values from corresponding pixel neighborhoods can be determined406 for individual pixels of this fast history frame. A range ofexpected pixel values can then be determined 408 as a function of thoseneighborhood values. A corresponding pixel value from a full historicalframe can be determined and compared 410 against this expected range. Ifit is determined 412 that the fast historical value is within theexpected range, then the actual historical value from the full historyframe can be used for this pixel location. If the fast historical valueis outside this range, then a determination can be made to clamp 416 thefull history value to the closest value within this expected range, suchas by using a min/max or projection-based approach as discussed herein.Once such a determination is made for all relevant pixels, the values ofthe current frame can be blended 418 with the clamped or actual valuesof the corresponding pixels of the historical frame. Once completed,this reconstructed image can be provided 420 for presentation, such asthrough a display as part of a gaming experience. Further, updated fastand full historical frames can be generated 422 using temporalaccumulation with this newly reconstructed image, and these historicalframes can be stored using respective buffers for use in reconstructinga next image or frame in this sequence.

In at least one embodiment, an alternative process can be performedwherein blending can occur earlier in the process, such as at step 404instead of step 418. In such an embodiment, the value can be clamped fora full historical frame that already contains the current frame value.While both approaches can produce acceptable results, one approach maybe easier to implement in certain situations.

In order to further improve the appearance of generated images, someamount of blur (e.g., Gaussian blur) or other spatial filtering can beapplied to dynamic scenes. This blur can help to smooth images in asequence to provide for more natural motion, and can also help to reducethe presence of spatial sampling bias and artifacts such as noise orflickering. It can be difficult to determine the appropriate amount ofblur to be applied to an image, as too much blur will reduce sharpnessof the image, while too little blur may not sufficiently remove theseand other such artifacts. Further, there may be portions of a scene withsignificant motion while other portions of that image are dynamic, suchthat it may be desirable to apply blur to portions with motion and notapply blur to portions that are static. As discussed herein, however, itcan be difficult to identify motion related to shadows, reflections, andother aspects that may relate from a process such as ray tracing, suchthat it can be difficult in existing approaches to determine how muchblur to apply to regions of an image associated with such aspect.

Accordingly, approaches in accordance with various embodiments canutilize information such as clamping determinations presented herein todetermine application of blurring, spatial filtering, or other suchimage processing. In a clamping process presented with respect to atleast one embodiment, clamping is applied when an amount of motion orchange in an image causes a historical pixel value from a fast imageframe to fall outside an expected range or region. Using such a process,a determination can be made for each pixel whether the pixel correspondsto a static portion of the image, a portion with an amount of motion orchange that is within an expected range, or an amount of motion orchange that is outside an expected range. In some embodiments, an amountof blur may be applied based on the pixel difference, regardless ofwhether that distance would result in clamping. An amount of blur orspatial filtering can be applied that may be different for any or all ofthese situations. In another example approach, a determination can bemade for each pixel as to a difference between a pixel value for a fasthistorical frame and a full historical frame. This difference in pixelvalue, or distance in color space, can be used to determine an amount ofblur to be applied or a weighting for a spatial filter. This differencecan be determined before or after temporal accumulation clamping, andthus can be based on the raw or clamped values. For large differences,or pixels where clamping was applied, a larger spatial filter can beapplied for those pixels. For smaller differences, a smaller spatialfilter can be applied. If the fast and full historical pixel values arethe same, within an allowable deviation, then no (or minimal) spatialfiltering may be applied in certain embodiments. In some embodiments aminimal amount of spatial filtering may be applied to an entire image,with this history-based spatial filtering acting as an additional filterfor pixels with greater degrees of motion or change.

In at least one embodiment, a difference can be calculated between thecolor of the full history and the color of the fast history, or betweenthe color of the full history and the clamped full history. It should beunderstood that “full” history in this case refers to a number ofhistory buffers accumulated in this image generation process at anygiven time, and does not require data from all previously generatedimages or frames in a sequence. This difference can be multiplied by aconstant or scalar to determine a weight for the spatial filter to beapplied. In at least one embodiment, this weighting can be used todetermine a radius of blur to be applied, such as may be a radius of 0,1, 2, or 3 pixels in any or all directions. Such an approach can be usedto apply only the amount of blur needed for specific regions of animage, which can minimize an overall amount of blur applied to an imageand thus result in a crisper image.

In at least one embodiment, temporal accumulation can be performed togenerate a fast historical frame and a full historical frame usingrespective blending weights. History clamping can then be performed forindividual pixel locations using determined neighborhoods of the fasthistory frame. In this example, a history confidence [0.0, 1.0] can becalculated, which is a function of the difference between the fullhistory value and the clamped full history value at a given pixellocation. This confidence value can be used as an indication of whichpixels were affected by history clamping, as well as an extent to whichthese pixels were affected in at least one embodiment. In this example,a default amount of spatial filtering (e.g., cross-bilateral spatialfiltering) can be applied to pixel locations in an image. Thedepth/normal bilateral weights can be set to a minimum, with aneffective radius being calculated (within a pre-defined maximum radius)based at least in part upon some form of noise estimate, as may relateto temporal variance, spatial variance, or total variation, among othersuch options. In at least one embodiment, an additional spatial filtercan be added that is a function of the history confidence calculatedbased on history clamping. In at least one embodiment, this can be alinear interpolation (“lerp”) given by lerp(MaxRadius, EffectiveRadius,HistoryConfidence). In at least one embodiment, HistoryConfidence can begiven byHistoryConfidence=saturate(abs(FullAccumulatedHistory−ClampedFullAccumulatedHistory)*ScalingFactor,where ScalingFactor can be any arbitrary scaling factor that has beendetermined to provide acceptable results for a given signal orimplementation. In this example, abs( ) is absolute value function andsaturate( ) clamps this value to a [0.0, 1.0] range. If there was noclamping for a pixel location, then no additional spatial filtering maybe applied. In at least some embodiments, an amount of additionalspatial filtering applied can be a factor of the difference between thepixel values for a given pixel in the fast historical frame versus thefull historical frame.

FIG. 5 illustrates an example system 500 that can be utilized inaccordance with various embodiments. This system carries over referencenumbers for similar components from FIG. 2, but it should be understoodthat this is for simplicity of explanation and should not be read as alimitation on the scope or variability of the various embodiments. Insuch a system, fast history and full history frames can be generated bya history manager component 214 as discussed previously. The fasthistory frame can be compared against a current frame to determinewhether to apply clamping for specific pixel locations or regions of thefull history frame. As mentioned, information from this clampingdetermination process can be used to determine an amount of spatialfiltering to be applied during image reconstruction. In this example,clamping information can be passed from a clamping module 220 to aspatial filter module 502. In other embodiments, the spatial filtermodule 502 may act directly on the fast history and full history frames.The spatial filter module 502 can determine information such as whetherclamping was applied and a difference between pixel values forcorresponding pixel locations in the fast historical image and the fullhistorical image. The spatial filter module 502 can then determine asize of a spatial filter or an amount of blur to be applied to eachpixel of an image generated by the reconstruction module 208, which mayinclude a single per-pixel determination, or may include a defaultfilter amount plus any additional filtering determined from the clampingor historical confidence data. The reconstructed image with thisadditional filtering applied can then be provided for display, as wellas provided to the history manager 214 for accumulation into updatedfull and fast historical frames for reconstruction of a next image orframe in this sequence.

FIG. 6 illustrates an example process 600 for determining spatialfiltering to apply to an image during reconstruction that can beutilized in accordance with various embodiments. In this example, aclamping-based approach will be described, but as discussed hereinhistory confidence values can be determined using other information aswell. Fast and full historical frames are obtained 602 from a temporalaccumulation process. It can be determined 604 whether to apply clampingto individual pixels of the full historical frame based at least in partupon values from pixels of corresponding pixel neighborhoods of the fasthistorical frame, such as whether the pixel value of a current framefalls within an expected range based on a given pixel neighborhood. Ahistory confidence value can then be calculated 606 for individual pixellocations that may be a function of the full history value and theclamped history value. If a clamped value is not used, there can be highconfidence in the full historical pixel value. For the pixels of theimage, a default spatial filtering can be determined 608 to be appliedduring reconstruction. Further, any additional spatial filtering to beapplied can be determined 610 based at least in part upon the historyconfidence value, where lower confidence corresponding to largerdifferences in pixel values may result in greater amounts of spatialfiltering, such as use of a larger bias radius. The default andadditional spatial bias can then be caused 612 to be applied to therespective pixels during image reconstruction. In this way, spatialfiltering can be minimized for more static portions of an image.

As mentioned, such an approach can be advantageous when dealing withdenoising of dynamic scenes. History clamping as discussed herein canhelp to detect stale history, and in instances where the stale historyis detected it can be determined to temporarily bump a blending factorduring temporal accumulation so that a heavier weight is assigned to themost recent data. While this may adequately address temporal lag,limiting a number of frames in temporal accumulation may introduce anunacceptable amount of noise. Since the system cannot rely on temporaldata to remove this noise, a spatial bias can be increased in locationswhere stale history was detected in order to provide for enhanceddenoising.

Other approaches for determining and applying spatial bias can be usedas well in other embodiments, such as for determining temporal orspatial gradients, which may be independent of history clamping. Suchgradients may be determined for an A-SGVF process, discussed previously.In another example, a velocity of occlusion can be used as a factor fordetermining whether to apply an additional, or increased, amount ofspatial filtering during image reconstruction, as ambient occlusion canprovide another confidence metric for anything that uses historicalpixel data. Ambient occlusion is a feature of a process such as raytracing, which may be used in a high definition render pipeline (HDRP).Ambient occlusion can be used to calculate an exposure of each point ina scene to ambient lighting. Other types of occlusion determinations canbe used as well for other light sources, etc. A determined velocity ofan occlusion, or occlude, can indicate whether, and how much, to trusthistorical pixel data. Rays from a given light source can be traced todetermine whether the corresponding geometry is moving, changing, orstatic, as well as an amount of movement or change. In some cases, onlya binary decision may be provided as to whether a pixel is static ordynamic based on occlusion velocity. In cases where velocity data isprovided or determined, the blur radius or weight of the spatial filtercan be increased with increases in velocity. Further, in someembodiments where HistoryConfidence may be somewhat temporally unstable,this value can be re-projected and slightly increased over a few framesin order to make a spatial filter bias temporally smoother. Such anapproach can help with denoising an otherwise improving image quality insituations where stale history data is detected.

Data Center

FIG. 7 illustrates an example data center 700, in which at least oneembodiment may be used. In at least one embodiment, data center 700includes a data center infrastructure layer 710, a framework layer 720,a software layer 730, and an application layer 740.

In at least one embodiment, as shown in FIG. 7, data centerinfrastructure layer 710 may include a resource orchestrator 712,grouped computing resources 714, and node computing resources (“nodeC.R.s”) 716(1)-716(N), where “N” represents any whole, positive integer.In at least one embodiment, node C.R.s 716(1)-716(N) may include, butare not limited to, any number of central processing units (“CPUs”) orother processors (including accelerators, field programmable gate arrays(FPGAs), graphics processors, etc.), memory devices (e.g., dynamicread-only memory), storage devices (e.g., solid state or disk drives),network input/output (“NW I/O”) devices, network switches, virtualmachines (“VMs”), power modules, and cooling modules, etc. In at leastone embodiment, one or more node C.R.s from among node C.R.s716(1)-716(N) may be a server having one or more of above-mentionedcomputing resources.

In at least one embodiment, grouped computing resources 714 may includeseparate groupings of node C.R.s housed within one or more racks (notshown), or many racks housed in data centers at various geographicallocations (also not shown). Separate groupings of node C.R.s withingrouped computing resources 714 may include grouped compute, network,memory or storage resources that may be configured or allocated tosupport one or more workloads. In at least one embodiment, several nodeC.R.s including CPUs or processors may grouped within one or more racksto provide compute resources to support one or more workloads. In atleast one embodiment, one or more racks may also include any number ofpower modules, cooling modules, and network switches, in anycombination.

In at least one embodiment, resource orchestrator 712 may configure orotherwise control one or more node C.R.s 716(1)-716(N) and/or groupedcomputing resources 714. In at least one embodiment, resourceorchestrator 712 may include a software design infrastructure (“SDI”)management entity for data center 700. In at least one embodiment,resource orchestrator may include hardware, software or some combinationthereof.

In at least one embodiment, as shown in FIG. 7, framework layer 720includes a job scheduler 722, a configuration manager 724, a resourcemanager 726 and a distributed file system 728. In at least oneembodiment, framework layer 720 may include a framework to supportsoftware 732 of software layer 730 and/or one or more application(s) 742of application layer 740. In at least one embodiment, software 732 orapplication(s) 742 may respectively include web-based service softwareor applications, such as those provided by Amazon Web Services, GoogleCloud and Microsoft Azure. In at least one embodiment, framework layer720 may be, but is not limited to, a type of free and open-sourcesoftware web application framework such as Apache Spark™ (hereinafter“Spark”) that may utilize distributed file system 728 for large-scaledata processing (e.g., “big data”). In at least one embodiment, jobscheduler 722 may include a Spark driver to facilitate scheduling ofworkloads supported by various layers of data center 700. In at leastone embodiment, configuration manager 724 may be capable of configuringdifferent layers such as software layer 730 and framework layer 720including Spark and distributed file system 728 for supportinglarge-scale data processing. In at least one embodiment, resourcemanager 726 may be capable of managing clustered or grouped computingresources mapped to or allocated for support of distributed file system728 and job scheduler 722. In at least one embodiment, clustered orgrouped computing resources may include grouped computing resource 714at data center infrastructure layer 710. In at least one embodiment,resource manager 726 may coordinate with resource orchestrator 712 tomanage these mapped or allocated computing resources.

In at least one embodiment, software 732 included in software layer 730may include software used by at least portions of node C.R.s716(1)-716(N), grouped computing resources 714, and/or distributed filesystem 728 of framework layer 720. The one or more types of software mayinclude, but are not limited to, Internet web page search software,e-mail virus scan software, database software, and streaming videocontent software.

In at least one embodiment, application(s) 742 included in applicationlayer 740 may include one or more types of applications used by at leastportions of node C.R.s 716(1)-716(N), grouped computing resources 714,and/or distributed file system 728 of framework layer 720. One or moretypes of applications may include, but are not limited to, any number ofa genomics application, a cognitive compute, and a machine learningapplication, including training or inferencing software, machinelearning framework software (e.g., PyTorch, TensorFlow, Caffe, etc.) orother machine learning applications used in conjunction with one or moreembodiments.

In at least one embodiment, any of configuration manager 724, resourcemanager 726, and resource orchestrator 712 may implement any number andtype of self-modifying actions based on any amount and type of dataacquired in any technically feasible fashion. In at least oneembodiment, self-modifying actions may relieve a data center operator ofdata center 700 from making possibly bad configuration decisions andpossibly avoiding underutilized and/or poor performing portions of adata center.

In at least one embodiment, data center 700 may include tools, services,software or other resources to train one or more machine learning modelsor predict or infer information using one or more machine learningmodels according to one or more embodiments described herein. Forexample, in at least one embodiment, a machine learning model may betrained by calculating weight parameters according to a neural networkarchitecture using software and computing resources described above withrespect to data center 700. In at least one embodiment, trained machinelearning models corresponding to one or more neural networks may be usedto infer or predict information using resources described above withrespect to data center 700 by using weight parameters calculated throughone or more training techniques described herein.

In at least one embodiment, data center may use CPUs,application-specific integrated circuits (ASICs), GPUs, FPGAs, or otherhardware to perform training and/or inferencing using above-describedresources. Moreover, one or more software and/or hardware resourcesdescribed above may be configured as a service to allow users to trainor performing inferencing of information, such as image recognition,speech recognition, or other artificial intelligence services.

Such components can be used to improve image quality during imagereconstruction using fast history-based clamping and differencedeterminations.

Computer Systems

FIG. 8 is a block diagram illustrating an exemplary computer system,which may be a system with interconnected devices and components, asystem-on-a-chip (SOC) or some combination thereof 800 formed with aprocessor that may include execution units to execute an instruction,according to at least one embodiment. In at least one embodiment,computer system 800 may include, without limitation, a component, suchas a processor 802 to employ execution units including logic to performalgorithms for process data, in accordance with present disclosure, suchas in embodiment described herein. In at least one embodiment, computersystem 800 may include processors, such as PENTIUM® Processor family,Xeon™, Itanium®, XScale™ and/or StrongARM™, Intel® Core™, or Intel®Nervana™ microprocessors available from Intel Corporation of SantaClara, Calif., although other systems (including PCs having othermicroprocessors, engineering workstations, set-top boxes and like) mayalso be used. In at least one embodiment, computer system 800 mayexecute a version of WINDOWS' operating system available from MicrosoftCorporation of Redmond, Wash., although other operating systems (UNIXand Linux for example), embedded software, and/or graphical userinterfaces, may also be used.

Embodiments may be used in other devices such as handheld devices andembedded applications. Some examples of handheld devices includecellular phones, Internet Protocol devices, digital cameras, personaldigital assistants (“PDAs”), and handheld PCs. In at least oneembodiment, embedded applications may include a microcontroller, adigital signal processor (“DSP”), system on a chip, network computers(“NetPCs”), set-top boxes, network hubs, wide area network (“WAN”)switches, or any other system that may perform one or more instructionsin accordance with at least one embodiment.

In at least one embodiment, computer system 800 may include, withoutlimitation, processor 802 that may include, without limitation, one ormore execution units 808 to perform machine learning model trainingand/or inferencing according to techniques described herein. In at leastone embodiment, computer system 800 is a single processor desktop orserver system, but in another embodiment computer system 800 may be amultiprocessor system. In at least one embodiment, processor 802 mayinclude, without limitation, a complex instruction set computer (“CISC”)microprocessor, a reduced instruction set computing (“RISC”)microprocessor, a very long instruction word (“VLIW”) microprocessor, aprocessor implementing a combination of instruction sets, or any otherprocessor device, such as a digital signal processor, for example. In atleast one embodiment, processor 802 may be coupled to a processor bus810 that may transmit data signals between processor 802 and othercomponents in computer system 800.

In at least one embodiment, processor 802 may include, withoutlimitation, a Level 1 (“L1”) internal cache memory (“cache”) 804. In atleast one embodiment, processor 802 may have a single internal cache ormultiple levels of internal cache. In at least one embodiment, cachememory may reside external to processor 802. Other embodiments may alsoinclude a combination of both internal and external caches depending onparticular implementation and needs. In at least one embodiment,register file 806 may store different types of data in various registersincluding, without limitation, integer registers, floating pointregisters, status registers, and instruction pointer register.

In at least one embodiment, execution unit 808, including, withoutlimitation, logic to perform integer and floating point operations, alsoresides in processor 802. In at least one embodiment, processor 802 mayalso include a microcode (“ucode”) read only memory (“ROM”) that storesmicrocode for certain macro instructions. In at least one embodiment,execution unit 808 may include logic to handle a packed instruction set809. In at least one embodiment, by including packed instruction set 809in an instruction set of a general-purpose processor 802, along withassociated circuitry to execute instructions, operations used by manymultimedia applications may be performed using packed data in ageneral-purpose processor 802. In one or more embodiments, manymultimedia applications may be accelerated and executed more efficientlyby using full width of a processor's data bus for performing operationson packed data, which may eliminate need to transfer smaller units ofdata across processor's data bus to perform one or more operations onedata element at a time.

In at least one embodiment, execution unit 808 may also be used inmicrocontrollers, embedded processors, graphics devices, DSPs, and othertypes of logic circuits. In at least one embodiment, computer system 800may include, without limitation, a memory 820. In at least oneembodiment, memory 820 may be implemented as a Dynamic Random AccessMemory (“DRAM”) device, a Static Random Access Memory (“SRAM”) device,flash memory device, or other memory device. In at least one embodiment,memory 820 may store instruction(s) 819 and/or data 821 represented bydata signals that may be executed by processor 802.

In at least one embodiment, system logic chip may be coupled toprocessor bus 810 and memory 820. In at least one embodiment, systemlogic chip may include, without limitation, a memory controller hub(“MCH”) 816, and processor 802 may communicate with MCH 816 viaprocessor bus 810. In at least one embodiment, MCH 816 may provide ahigh bandwidth memory path 818 to memory 820 for instruction and datastorage and for storage of graphics commands, data and textures. In atleast one embodiment, MCH 816 may direct data signals between processor802, memory 820, and other components in computer system 800 and tobridge data signals between processor bus 810, memory 820, and a systemI/O 822. In at least one embodiment, system logic chip may provide agraphics port for coupling to a graphics controller. In at least oneembodiment, MCH 816 may be coupled to memory 820 through a highbandwidth memory path 818 and graphics/video card 812 may be coupled toMCH 816 through an Accelerated Graphics Port (“AGP”) interconnect 814.

In at least one embodiment, computer system 800 may use system I/O 822that is a proprietary hub interface bus to couple MCH 816 to I/Ocontroller hub (“ICH”) 830. In at least one embodiment, ICH 830 mayprovide direct connections to some I/O devices via a local I/O bus. Inat least one embodiment, local I/O bus may include, without limitation,a high-speed I/O bus for connecting peripherals to memory 820, chipset,and processor 802. Examples may include, without limitation, an audiocontroller 829, a firmware hub (“flash BIOS”) 828, a wirelesstransceiver 826, a data storage 824, a legacy I/O controller 823containing user input and keyboard interfaces 825, a serial expansionport 827, such as Universal Serial Bus (“USB”), and a network controller834. Data storage 824 may comprise a hard disk drive, a floppy diskdrive, a CD-ROM device, a flash memory device, or other mass storagedevice.

In at least one embodiment, FIG. 8 illustrates a system, which includesinterconnected hardware devices or “chips”, whereas in otherembodiments, FIG. 8 may illustrate an exemplary System on a Chip(“SoC”). In at least one embodiment, devices may be interconnected withproprietary interconnects, standardized interconnects (e.g., PCIe) orsome combination thereof. In at least one embodiment, one or morecomponents of computer system 800 are interconnected using computeexpress link (CXL) interconnects.

Such components can be used to improve image quality during imagereconstruction using fast history-based clamping and differencedeterminations.

FIG. 9 is a block diagram illustrating an electronic device 900 forutilizing a processor 910, according to at least one embodiment. In atleast one embodiment, electronic device 900 may be, for example andwithout limitation, a notebook, a tower server, a rack server, a bladeserver, a laptop, a desktop, a tablet, a mobile device, a phone, anembedded computer, or any other suitable electronic device.

In at least one embodiment, system 900 may include, without limitation,processor 910 communicatively coupled to any suitable number or kind ofcomponents, peripherals, modules, or devices. In at least oneembodiment, processor 910 coupled using a bus or interface, such as a 1°C. bus, a System Management Bus (“SMBus”), a Low Pin Count (LPC) bus, aSerial Peripheral Interface (“SPI”), a High Definition Audio (“HDA”)bus, a Serial Advance Technology Attachment (“SATA”) bus, a UniversalSerial Bus (“USB”) (versions 1, 2, 3), or a Universal AsynchronousReceiver/Transmitter (“UART”) bus. In at least one embodiment, FIG. 9illustrates a system, which includes interconnected hardware devices or“chips”, whereas in other embodiments, FIG. 9 may illustrate anexemplary System on a Chip (“SoC”). In at least one embodiment, devicesillustrated in FIG. 9 may be interconnected with proprietaryinterconnects, standardized interconnects (e.g., PCIe) or somecombination thereof. In at least one embodiment, one or more componentsof FIG. 9 are interconnected using compute express link (CXL)interconnects.

In at least one embodiment, FIG. 9 may include a display 924, a touchscreen 925, a touch pad 930, a Near Field Communications unit (“NFC”)945, a sensor hub 940, a thermal sensor 946, an Express Chipset (“EC”)935, a Trusted Platform Module (“TPM”) 938, BIOS/firmware/flash memory(“BIOS, FW Flash”) 922, a DSP 960, a drive 920 such as a Solid StateDisk (“SSD”) or a Hard Disk Drive (“HDD”), a wireless local area networkunit (“WLAN”) 950, a Bluetooth unit 952, a Wireless Wide Area Networkunit (“WWAN”) 956, a Global Positioning System (GPS) 955, a camera (“USB3.0 camera”) 954 such as a USB 3.0 camera, and/or a Low Power DoubleData Rate (“LPDDR”) memory unit (“LPDDR3”) 915 implemented in, forexample, LPDDR3 standard. These components may each be implemented inany suitable manner.

In at least one embodiment, other components may be communicativelycoupled to processor 910 through components discussed above. In at leastone embodiment, an accelerometer 941, Ambient Light Sensor (“ALS”) 942,compass 943, and a gyroscope 944 may be communicatively coupled tosensor hub 940. In at least one embodiment, thermal sensor 939, a fan937, a keyboard 946, and a touch pad 930 may be communicatively coupledto EC 935. In at least one embodiment, speaker 963, headphones 964, andmicrophone (“mic”) 965 may be communicatively coupled to an audio unit(“audio codec and class d amp”) 962, which may in turn becommunicatively coupled to DSP 960. In at least one embodiment, audiounit 964 may include, for example and without limitation, an audiocoder/decoder (“codec”) and a class D amplifier. In at least oneembodiment, SIM card (“SIM”) 957 may be communicatively coupled to WWANunit 956. In at least one embodiment, components such as WLAN unit 950and

Bluetooth unit 952, as well as WWAN unit 956 may be implemented in aNext Generation Form Factor (“NGFF”).

Such components can be used to improve image quality during imagereconstruction using fast history-based clamping and differencedeterminations.

FIG. 10 is a block diagram of a processing system, according to at leastone embodiment. In at least one embodiment, system 1000 includes one ormore processors 1002 and one or more graphics processors 1008, and maybe a single processor desktop system, a multiprocessor workstationsystem, or a server system having a large number of processors 1002 orprocessor cores 1007. In at least one embodiment, system 1000 is aprocessing platform incorporated within a system-on-a-chip (SoC)integrated circuit for use in mobile, handheld, or embedded devices.

In at least one embodiment, system 1000 can include, or be incorporatedwithin a server-based gaming platform, a game console, including a gameand media console, a mobile gaming console, a handheld game console, oran online game console. In at least one embodiment, system 1000 is amobile phone, smart phone, tablet computing device or mobile Internetdevice. In at least one embodiment, processing system 1000 can alsoinclude, couple with, or be integrated within a wearable device, such asa smart watch wearable device, smart eyewear device, augmented realitydevice, or virtual reality device. In at least one embodiment,processing system 1000 is a television or set top box device having oneor more processors 1002 and a graphical interface generated by one ormore graphics processors 1008.

In at least one embodiment, one or more processors 1002 each include oneor more processor cores 1007 to process instructions which, whenexecuted, perform operations for system and user software. In at leastone embodiment, each of one or more processor cores 1007 is configuredto process a specific instruction set 1009. In at least one embodiment,instruction set 1009 may facilitate Complex Instruction Set Computing(CISC), Reduced Instruction Set Computing (RISC), or computing via aVery Long Instruction Word (VLIW). In at least one embodiment, processorcores 1007 may each process a different instruction set 1009, which mayinclude instructions to facilitate emulation of other instruction sets.In at least one embodiment, processor core 1007 may also include otherprocessing devices, such a Digital Signal Processor (DSP).

In at least one embodiment, processor 1002 includes cache memory 1004.In at least one embodiment, processor 1002 can have a single internalcache or multiple levels of internal cache. In at least one embodiment,cache memory is shared among various components of processor 1002. In atleast one embodiment, processor 1002 also uses an external cache (e.g.,a Level-3 (L3) cache or Last Level Cache (LLC)) (not shown), which maybe shared among processor cores 1007 using known cache coherencytechniques. In at least one embodiment, register file 1006 isadditionally included in processor 1002 which may include differenttypes of registers for storing different types of data (e.g., integerregisters, floating point registers, status registers, and aninstruction pointer register). In at least one embodiment, register file1006 may include general-purpose registers or other registers.

In at least one embodiment, one or more processor(s) 1002 are coupledwith one or more interface bus(es) 1010 to transmit communicationsignals such as address, data, or control signals between processor 1002and other components in system 1000. In at least one embodiment,interface bus 1010, in one embodiment, can be a processor bus, such as aversion of a Direct Media Interface (DMI) bus. In at least oneembodiment, interface 1010 is not limited to a DMI bus, and may includeone or more Peripheral Component Interconnect buses (e.g., PCI, PCIExpress), memory busses, or other types of interface busses. In at leastone embodiment processor(s) 1002 include an integrated memory controller1016 and a platform controller hub 1030. In at least one embodiment,memory controller 1016 facilitates communication between a memory deviceand other components of system 1000, while platform controller hub (PCH)1030 provides connections to I/O devices via a local I/O bus.

In at least one embodiment, memory device 1020 can be a dynamic randomaccess memory (DRAM) device, a static random access memory (SRAM)device, flash memory device, phase-change memory device, or some othermemory device having suitable performance to serve as process memory. Inat least one embodiment memory device 1020 can operate as system memoryfor system 1000, to store data 1022 and instructions 1021 for use whenone or more processors 1002 executes an application or process. In atleast one embodiment, memory controller 1016 also couples with anoptional external graphics processor 1012, which may communicate withone or more graphics processors 1008 in processors 1002 to performgraphics and media operations. In at least one embodiment, a displaydevice 1011 can connect to processor(s) 1002. In at least one embodimentdisplay device 1011 can include one or more of an internal displaydevice, as in a mobile electronic device or a laptop device or anexternal display device attached via a display interface (e.g.,DisplayPort, etc.). In at least one embodiment, display device 1011 caninclude a head mounted display (HMD) such as a stereoscopic displaydevice for use in virtual reality (VR) applications or augmented reality(AR) applications.

In at least one embodiment, platform controller hub 1030 enablesperipherals to connect to memory device 1020 and processor 1002 via ahigh-speed I/O bus. In at least one embodiment, I/O peripherals include,but are not limited to, an audio controller 1046, a network controller1034, a firmware interface 1028, a wireless transceiver 1026, touchsensors 1025, a data storage device 1024 (e.g., hard disk drive, flashmemory, etc.). In at least one embodiment, data storage device 1024 canconnect via a storage interface (e.g., SATA) or via a peripheral bus,such as a Peripheral Component Interconnect bus (e.g., PCI, PCIExpress). In at least one embodiment, touch sensors 1025 can includetouch screen sensors, pressure sensors, or fingerprint sensors. In atleast one embodiment, wireless transceiver 1026 can be a Wi-Fitransceiver, a Bluetooth transceiver, or a mobile network transceiversuch as a 3G, 4G, or Long Term Evolution (LTE) transceiver. In at leastone embodiment, firmware interface 1028 enables communication withsystem firmware, and can be, for example, a unified extensible firmwareinterface (UEFI). In at least one embodiment, network controller 1034can enable a network connection to a wired network. In at least oneembodiment, a high-performance network controller (not shown) coupleswith interface bus 1010. In at least one embodiment, audio controller1046 is a multi-channel high definition audio controller. In at leastone embodiment, system 1000 includes an optional legacy I/O controller1040 for coupling legacy (e.g., Personal System 2 (PS/2)) devices tosystem. In at least one embodiment, platform controller hub 1030 canalso connect to one or more Universal Serial Bus (USB) controllers 1042connect input devices, such as keyboard and mouse 1043 combinations, acamera 1044, or other USB input devices.

In at least one embodiment, an instance of memory controller 1016 andplatform controller hub 1030 may be integrated into a discreet externalgraphics processor, such as external graphics processor 1012. In atleast one embodiment, platform controller hub 1030 and/or memorycontroller 1016 may be external to one or more processor(s) 1002. Forexample, in at least one embodiment, system 1000 can include an externalmemory controller 1016 and platform controller hub 1030, which may beconfigured as a memory controller hub and peripheral controller hubwithin a system chipset that is in communication with processor(s) 1002.

Such components can be used to improve image quality during imagereconstruction using fast history-based clamping and differencedeterminations.

FIG. 11 is a block diagram of a processor 1100 having one or moreprocessor cores 1102A-1102N, an integrated memory controller 1114, andan integrated graphics processor 1108, according to at least oneembodiment. In at least one embodiment, processor 1100 can includeadditional cores up to and including additional core 1102N representedby dashed lined boxes. In at least one embodiment, each of processorcores 1102A-1102N includes one or more internal cache units 1104A-1104N.In at least one embodiment, each processor core also has access to oneor more shared cached units 1106.

In at least one embodiment, internal cache units 1104A-1104N and sharedcache units 1106 represent a cache memory hierarchy within processor1100. In at least one embodiment, cache memory units 1104A-1104N mayinclude at least one level of instruction and data cache within eachprocessor core and one or more levels of shared mid-level cache, such asa Level 2 (L2), Level 3 (L3), Level 4 (L4), or other levels of cache,where a highest level of cache before external memory is classified asan LLC. In at least one embodiment, cache coherency logic maintainscoherency between various cache units 1106 and 1104A-1104N.

In at least one embodiment, processor 1100 may also include a set of oneor more bus controller units 1116 and a system agent core 1110. In atleast one embodiment, one or more bus controller units 1116 manage a setof peripheral buses, such as one or more PCI or PCI express busses. Inat least one embodiment, system agent core 1110 provides managementfunctionality for various processor components. In at least oneembodiment, system agent core 1110 includes one or more integratedmemory controllers 1114 to manage access to various external memorydevices (not shown).

In at least one embodiment, one or more of processor cores 1102A-1102Ninclude support for simultaneous multi-threading. In at least oneembodiment, system agent core 1110 includes components for coordinatingand operating cores 1102A-1102N during multi-threaded processing. In atleast one embodiment, system agent core 1110 may additionally include apower control unit (PCU), which includes logic and components toregulate one or more power states of processor cores 1102A-1102N andgraphics processor 1108.

In at least one embodiment, processor 1100 additionally includesgraphics processor 1108 to execute graphics processing operations. In atleast one embodiment, graphics processor 1108 couples with shared cacheunits 1106, and system agent core 1110, including one or more integratedmemory controllers 1114. In at least one embodiment, system agent core1110 also includes a display controller 1111 to drive graphics processoroutput to one or more coupled displays. In at least one embodiment,display controller 1111 may also be a separate module coupled withgraphics processor 1108 via at least one interconnect, or may beintegrated within graphics processor 1108.

In at least one embodiment, a ring based interconnect unit 1112 is usedto couple internal components of processor 1100. In at least oneembodiment, an alternative interconnect unit may be used, such as apoint-to-point interconnect, a switched interconnect, or othertechniques. In at least one embodiment, graphics processor 1108 coupleswith ring interconnect 1112 via an I/O link 1113.

In at least one embodiment, I/O link 1113 represents at least one ofmultiple varieties of I/O interconnects, including an on package I/Ointerconnect which facilitates communication between various processorcomponents and a high-performance embedded memory module 1118, such asan eDRAM module. In at least one embodiment, each of processor cores1102A-1102N and graphics processor 1108 use embedded memory modules 1118as a shared Last Level Cache.

In at least one embodiment, processor cores 1102A-1102N are homogenouscores executing a common instruction set architecture. In at least oneembodiment, processor cores 1102A-1102N are heterogeneous in terms ofinstruction set architecture (ISA), where one or more of processor cores1102A-1102N execute a common instruction set, while one or more othercores of processor cores 1102A-1102N executes a subset of a commoninstruction set or a different instruction set. In at least oneembodiment, processor cores 1102A-1102N are heterogeneous in terms ofmicroarchitecture, where one or more cores having a relatively higherpower consumption couple with one or more power cores having a lowerpower consumption. In at least one embodiment, processor 1100 can beimplemented on one or more chips or as an SoC integrated circuit.

Such components can be used to improve image quality during imagereconstruction using fast history-based clamping and differencedeterminations.

Other variations are within spirit of present disclosure. Thus, whiledisclosed techniques are susceptible to various modifications andalternative constructions, certain illustrated embodiments thereof areshown in drawings and have been described above in detail. It should beunderstood, however, that there is no intention to limit disclosure tospecific form or forms disclosed, but on contrary, intention is to coverall modifications, alternative constructions, and equivalents fallingwithin spirit and scope of disclosure, as defined in appended claims.

Use of terms “a” and “an” and “the” and similar referents in context ofdescribing disclosed embodiments (especially in context of followingclaims) are to be construed to cover both singular and plural, unlessotherwise indicated herein or clearly contradicted by context, and notas a definition of a term. Terms “comprising,” “having,” “including,”and “containing” are to be construed as open-ended terms (meaning“including, but not limited to,”) unless otherwise noted. Term“connected,” when unmodified and referring to physical connections, isto be construed as partly or wholly contained within, attached to, orjoined together, even if there is something intervening. Recitation ofranges of values herein are merely intended to serve as a shorthandmethod of referring individually to each separate value falling withinrange, unless otherwise indicated herein and each separate value isincorporated into specification as if it were individually recitedherein. Use of term “set” (e.g., “a set of items”) or “subset,” unlessotherwise noted or contradicted by context, is to be construed as anonempty collection comprising one or more members. Further, unlessotherwise noted or contradicted by context, term “subset” of acorresponding set does not necessarily denote a proper subset ofcorresponding set, but subset and corresponding set may be equal.

Conjunctive language, such as phrases of form “at least one of A, B, andC,” or “at least one of A, B and C,” unless specifically statedotherwise or otherwise clearly contradicted by context, is otherwiseunderstood with context as used in general to present that an item,term, etc., may be either A or B or C, or any nonempty subset of set ofA and B and C. For instance, in illustrative example of a set havingthree members, conjunctive phrases “at least one of A, B, and C” and “atleast one of A, B and C” refer to any of following sets: {A}, {B}, {C},{A, B}, {A, C}, {B, C}, {A, B, C}. Thus, such conjunctive language isnot generally intended to imply that certain embodiments require atleast one of A, at least one of B, and at least one of C each to bepresent. In addition, unless otherwise noted or contradicted by context,term “plurality” indicates a state of being plural (e.g., “a pluralityof items” indicates multiple items). A plurality is at least two items,but can be more when so indicated either explicitly or by context.Further, unless stated otherwise or otherwise clear from context, phrase“based on” means “based at least in part on” and not “based solely on.”

Operations of processes described herein can be performed in anysuitable order unless otherwise indicated herein or otherwise clearlycontradicted by context. In at least one embodiment, a process such asthose processes described herein (or variations and/or combinationsthereof) is performed under control of one or more computer systemsconfigured with executable instructions and is implemented as code(e.g., executable instructions, one or more computer programs or one ormore applications) executing collectively on one or more processors, byhardware or combinations thereof. In at least one embodiment, code isstored on a computer-readable storage medium, for example, in form of acomputer program comprising a plurality of instructions executable byone or more processors. In at least one embodiment, a computer-readablestorage medium is a non-transitory computer-readable storage medium thatexcludes transitory signals (e.g., a propagating transient electric orelectromagnetic transmission) but includes non-transitory data storagecircuitry (e.g., buffers, cache, and queues) within transceivers oftransitory signals. In at least one embodiment, code (e.g., executablecode or source code) is stored on a set of one or more non-transitorycomputer-readable storage media having stored thereon executableinstructions (or other memory to store executable instructions) that,when executed (i.e., as a result of being executed) by one or moreprocessors of a computer system, cause computer system to performoperations described herein. A set of non-transitory computer-readablestorage media, in at least one embodiment, comprises multiplenon-transitory computer-readable storage media and one or more ofindividual non-transitory storage media of multiple non-transitorycomputer-readable storage media lack all of code while multiplenon-transitory computer-readable storage media collectively store all ofcode. In at least one embodiment, executable instructions are executedsuch that different instructions are executed by differentprocessors—for example, a non-transitory computer-readable storagemedium store instructions and a main central processing unit (“CPU”)executes some of instructions while a graphics processing unit (“GPU”)executes other instructions. In at least one embodiment, differentcomponents of a computer system have separate processors and differentprocessors execute different subsets of instructions.

Accordingly, in at least one embodiment, computer systems are configuredto implement one or more services that singly or collectively performoperations of processes described herein and such computer systems areconfigured with applicable hardware and/or software that enableperformance of operations. Further, a computer system that implements atleast one embodiment of present disclosure is a single device and, inanother embodiment, is a distributed computer system comprising multipledevices that operate differently such that distributed computer systemperforms operations described herein and such that a single device doesnot perform all operations.

Use of any and all examples, or exemplary language (e.g., “such as”)provided herein, is intended merely to better illuminate embodiments ofdisclosure and does not pose a limitation on scope of disclosure unlessotherwise claimed. No language in specification should be construed asindicating any non-claimed element as essential to practice ofdisclosure.

All references, including publications, patent applications, andpatents, cited herein are hereby incorporated by reference to sameextent as if each reference were individually and specifically indicatedto be incorporated by reference and were set forth in its entiretyherein.

In description and claims, terms “coupled” and “connected,” along withtheir derivatives, may be used. It should be understood that these termsmay be not intended as synonyms for each other. Rather, in particularexamples, “connected” or “coupled” may be used to indicate that two ormore elements are in direct or indirect physical or electrical contactwith each other. “Coupled” may also mean that two or more elements arenot in direct contact with each other, but yet still co-operate orinteract with each other.

Unless specifically stated otherwise, it may be appreciated thatthroughout specification terms such as “processing,” “computing,”“calculating,” “determining,” or like, refer to action and/or processesof a computer or computing system, or similar electronic computingdevice, that manipulate and/or transform data represented as physical,such as electronic, quantities within computing system's registersand/or memories into other data similarly represented as physicalquantities within computing system's memories, registers or other suchinformation storage, transmission or display devices.

In a similar manner, term “processor” may refer to any device or portionof a device that processes electronic data from registers and/or memoryand transform that electronic data into other electronic data that maybe stored in registers and/or memory. As non-limiting examples,“processor” may be a CPU or a GPU. A “computing platform” may compriseone or more processors. As used herein, “software” processes mayinclude, for example, software and/or hardware entities that performwork over time, such as tasks, threads, and intelligent agents. Also,each process may refer to multiple processes, for carrying outinstructions in sequence or in parallel, continuously or intermittently.Terms “system” and “method” are used herein interchangeably insofar assystem may embody one or more methods and methods may be considered asystem.

In present document, references may be made to obtaining, acquiring,receiving, or inputting analog or digital data into a subsystem,computer system, or computer-implemented machine. Obtaining, acquiring,receiving, or inputting analog and digital data can be accomplished in avariety of ways such as by receiving data as a parameter of a functioncall or a call to an application programming interface. In someimplementations, process of obtaining, acquiring, receiving, orinputting analog or digital data can be accomplished by transferringdata via a serial or parallel interface. In another implementation,process of obtaining, acquiring, receiving, or inputting analog ordigital data can be accomplished by transferring data via a computernetwork from providing entity to acquiring entity. References may alsobe made to providing, outputting, transmitting, sending, or presentinganalog or digital data. In various examples, process of providing,outputting, transmitting, sending, or presenting analog or digital datacan be accomplished by transferring data as an input or output parameterof a function call, a parameter of an application programming interfaceor interprocess communication mechanism.

Although discussion above sets forth example implementations ofdescribed techniques, other architectures may be used to implementdescribed functionality, and are intended to be within scope of thisdisclosure. Furthermore, although specific distributions ofresponsibilities are defined above for purposes of discussion, variousfunctions and responsibilities might be distributed and divided indifferent ways, depending on circumstances.

Furthermore, although subject matter has been described in languagespecific to structural features and/or methodological acts, it is to beunderstood that subject matter claimed in appended claims is notnecessarily limited to specific features or acts described. Rather,specific features and acts are disclosed as exemplary forms ofimplementing the claims.

What is claimed is:
 1. A method, comprising: generating a fasthistorical frame for a rendered frame; determining, from the fasthistorical frame, a range of expected pixel values for a pixel location;determining that a historical pixel value for the pixel location, from afull historical frame, is outside the range of expected pixel values;clamping the historical pixel value for the pixel location, from thefull historical frame, to a clamped historical value within the range ofexpected pixel values; determining an amount of spatial filtering to beapplied at the pixel location based at least in part upon a differencebetween the historical value and the clamped historical value; andperforming image reconstruction in part by blending a current value forthe pixel location of the current frame with the clamped historicalvalue and applying the determined amount of spatial filtering.
 2. Themethod of claim 1, further comprising: determining the amount of spatialfiltering to be applied using a filtering weight that corresponds to adifference between the historical value and the clamped historicalvalue, as multiplied by a specified scalar value.
 3. The method of claim1, wherein the amount of spatial filtering to be applied is in additionto a default amount of spatial filtering to be applied at one or morepixel locations during image reconstruction.
 4. The method of claim 1,wherein the amount of spatial filtering to be applied corresponds to ablur radius for a Gaussian blur to be applied at the pixel locationafter the blending.
 5. The method of claim 1, further comprising:providing an image resulting from the image reconstruction to a temporalaccumulation process for updating the fast historical frame and the fullhistorical frame and storing to respective buffers for the imagereconstruction.
 6. The method of claim 5, further comprising:determining a first temporal accumulation weight for generating the fasthistorical frame and a second temporal accumulation weight forgenerating the full historical frame, the first temporal accumulationweight being higher than the second temporal accumulation weight.
 7. Themethod of claim 6, wherein the first temporal accumulation weight isabout 0.5 and the second temporal accumulation weight is about 0.05. 8.The method of claim 1, wherein the range of expected pixel values isdetermined based at least in part upon a set of fast pixel valuesdetermined from a pixel neighborhood surrounding the pixel location inthe fast historical frame.
 9. The method of claim 1, further comprising:determining, from a second rendered frame, a second set of fast pixelvalues corresponding to a pixel location; determining a second range ofexpected pixel values based at least in part upon the second set of fastpixel values; determining that an updated historical pixel value fromthe full historical frame is within the second range of expected pixelvalues; and determining to apply only a default amount of spatialfiltering at the pixel location.
 10. A system, comprising: a processor;and memory including instructions that, when executed by the processor,cause the system to: generate a fast historical frame for a renderedframe; determine, from the fast historical frame, a range of expectedpixel values for a pixel location; determine that a historical pixelvalue for the pixel location, from a full historical frame, is outsidethe range of expected pixel values; clamp the historical pixel value forthe pixel location, from the full historical frame, to a clampedhistorical value within the range of expected pixel values; determine anamount of spatial filtering to be applied at the pixel location based atleast in part upon a difference between the historical value and theclamped historical value; and perform image reconstruction in part byblending a current value for the pixel location of the current with theclamped historical value and applying the determined amount of spatialfiltering.
 11. The system of claim 10, wherein the instructions whenexecuted further cause the system to: determine the amount of spatialfiltering to be applied using a filtering weight that corresponds to adifference between the historical value and the clamped historicalvalue, as multiplied by a specified scalar value.
 12. The system ofclaim 10, wherein the amount of spatial filtering to be applied is inaddition to a default amount of spatial filtering to be applied at pixellocations during image reconstruction.
 13. The system of claim 10,wherein the amount of spatial filtering to be applied corresponds to ablur radius for a Gaussian blur to be applied at the pixel locationafter the blending.
 14. The system of claim 10, wherein the instructionswhen executed further cause the system to: provide an image resultingfrom the image reconstruction to a temporal accumulation process forupdating the fast historical frame and the full historical frame andstoring to respective buffers for the image reconstruction.
 15. Thesystem of claim 14, wherein the instructions when executed further causethe system to: determine a first temporal accumulation weight forgenerating the fast historical frame and a second temporal accumulationweight for generating the full historical frame, the first temporalaccumulation weight being higher than the second temporal accumulationweight.